Wet Leak Seepage Fix for a Thru Hull?

[sww914]

The risk is too great, the reward too small, and the symptom too minor to try it in the water, unless all you're trying to do is goop around the outside of the through hull with something that won't make you suicidal when you have to deal with it later.

[HopCar]

It sounds like you have a valve screwed onto a thru-hull fitting and not a real flanged seacock. Like Cheechaco, I'd be worried about a crack in the thru-hull fitting. Messing with the valve could cause the thru-hull to break off. If you mess with it in the water, have a plug handy and the phone number of a yard you can call for an emergency haul out. Think about replacing the valve with a real seacock.

[westwinds]

Originally Posted by HopCar

It sounds like you have a valve screwed onto a thru-hull fitting and not a real flanged seacock... Think about replacing the valve with a real seacock.

Dezincafication of a brass valve making it likely to fail catastrophically in the near future?

[Charlie]

Originally Posted by sdowney717

Ok, I spent time looking at this very carefully yesterday.
And found it is seeping from the threads where the valve screws on not from the backing plate.

I figure if I do this in the water, I can unscrew it and coat with some teflon paste on the threads while putting a heavy lead weight and rubber gasket on top of the pipe to keep water out, or buy a pipe cap. It has been about 2 years since I had boat out and had this thing in my hands so it is likely still ok. It is a scoop type bronze pickup oval shaped thing on the bottom and I think it is 1.5 inch thread.

I kept wondering how it could be leaking as I know I sealed it very well, so at least I know now what is really happening with it.

I have replaced seacocks with out hauling. It isn't that difficult. Dive the bottom with a wooden plug and a thin rag. wrap the rag around the plug (it acts like a gasket) and force the plug into the thru hull. Have some one on the inside tell you if it has stopped leaking. Remove the thru hull and replace.

That said I would make sure that the threads that are on the thru hull and the seacock are the same. There are two different threads used in the assembly as a whole. One is NPS (national pipe straight) and the other is NPT (national pipe tapered) The two threads use a different method of sealing. The taper is sealed by torque. I don't know about the straight thread. Maine Sail goes over this well.
Seacock & Thru-Hull Primer/Pre Information Photo Gallery by Compass Marine at pbase.com


Here is a good article on thru hulls. Installing a Seacock - BoatTECH Guides by Don Casey | BoatUS

[sdowney717]

I got it apart and tried resealing but it still weeps a little same as before, so I think it might be the bronze scoop in the hull. Or the teflon sealer washed off which I doubt.

Needed handle off to spin off the assembly and had to remove rusty nut so used Kroil. Had to heat the elbow with a torch to get that apart. It all got liberal amount of teflon paste sealer going back together.

This Apollo valve has stainless handle, bronze body stainless ball valve, bronze shaft and stupidly a common steel nut.


Water fountain was shooting upwards like a fire house in the movies Not true.
Water pushed up about a foot and was easy to stop with the weight.

picture of Apollo valve.



very heavy lead weight with rubber pipe cap

[JohnNLiz]

I havn't replaced mine yet, but am planning to do so soon. I'm told by the old captain at my dock that a toilette plunger will keep the water out from the outside and a quick swap once it's loose can be done provided the hull is good and there is a well coordinated and ready set of hands on both sides once everything is loosed up. I have a solid fiberglass hull, so I'm not worried about core issues and if things start going awry an emergency plug can keep things under control until the right combination of gaskets are assembled if the first attempt isn't perfect.

The term three handed monkey screw comes to mind.....

[HopCar]

Watch this video about changing a seacock while in the water. The tool shown eliminates the need for a diver.

Seabung - Breach Control Technology
Seabung Breach Control

[sgancarz]

Originally Posted by HopCar

Watch this video about changing a seacock while in the water. The tool shown eliminates the need for a diver.

Seabung - Breach Control Technology
Seabung Breach Control

Looks like a great thing to have onboard. Ingenious yet simple design.